Tensile properties and strengthening mechanisms of a TWIP steel at high strain rate: Hall-Petch relationship

Resumen:
The influence of strain rate and grain size on the mechanical properties of a 22% Mn, 0.6% C (mass %) austenitic TWIP steel has been studied. A typical quasi-linear stress-strain behaviour of TWIP steels that deform by twinning has been observed at strain rates of 9.4 s(-1) and 265 s(-1) and room temperature. At high strain rates, the constant work - hardening rate region typically observed in TWIP steel clearly shortens. In addition, the Hall-Petch relationship has been obtained for each strain rate. The Hall-Petch slope K-HP increases as a function of strain in all cases. The dependence of the K-HP on the strain rate could be adiabatic heating.